KYOTO (Kyodo) Prosecutors are building a case against the former director and deputy director of the scandal-hit Japan Kanji Aptitude Testing Foundation for losing the organization money through improper business practices, investigative sources said Thursday.

At the center of the scandal are Noboru Okubo, 73, former director of the kanji proficiency test organizer, and his son, Hiroshi, 45, the former deputy director. The two also serve as senior officials of an advertising firm.

Okubo and his son are suspected of receiving ¥759 million worth of business orders from the kanji body at their ad agency over a three-year period to fiscal 2008 and commissioning the business to other companies for around ¥478 million.

Their ad agency thus made ¥281 million in unfair gains, while the kanji foundation suffered the loss, the sources alleged.

The foundation has voluntarily provided its account books to prosecutors, who are expected to launch a full-fledged investigation after the Kyoto-based body files a complaint against those involved in the case.

The aptitude tests by the foundation have steadily gained in popularity and the number of test-takers reached 2.7 million in fiscal 2007. The foundation is a public interest corporation whose profit-making activities are strictly limited.